Overview of Automatic Scratch Tester- Constant Load:
Coatings and paints can protect, decorate substrate or conceal the defects of a substrate and these three functions are related to coatings hardness. Hardness is an important performance for paint's mechanical strength, as well as an important indicator to judge paint quality. One of the important indicators to evaluate coatings hardness is scratch resistance.
ISO 1518 《Paints and varnishes -- Determination of scratch resistance》specifies a test method for determining under defined conditions the resistance of a single coating or a multi-coat system of paint, varnish or related product to penetration by scratching with a scratch stylus loaded with a specified load.
This test has been found to be useful in comparing the scratch resistance of different coatings. It is most useful in providing relative ratings for a series of coated panels exhibiting significant differences in scratch resistance.
Before 2011, there was only one standard used to scientifically evaluate paint scratch resistance under different applications. After revising this standard in 2011, this test method was divided into two parts: One is constant-loading, i.e the loading to panels is constant during the scratch test, and the test results are shown as the max. weight without damaging the coatings. The other is variable loading, i.e. the loading on which the stylus loads test panel is increased continuously from 0 during the whole test, then measure the distance to the final point where the paint begins to scratch. Testing results are shown as critical loads.
◆Large working table which can be positioned left and right—convenient for measuring different areas in the same panel
◆ Special fixing device for sample can test different size of substrates
◆ Sound-light Alarm system for puncturing through sample panel to make it more visual
◆ High hardness material stylus
Main Technical Parameters：
Standards: ISO 1518-1, BS 3900：E2
Stylus: Hemispherical hard-metal tip of radius .009in or 0.19in (0.25mm or 0.5mm) and Hemispherical synthetic-ruby of radius .009in or 0.19in (0.25mm or 0.5mm)
Angle between stylus and sample: 90°
Weight: Constant-loading (0.5N×1pc，1N×1pc，2N×2pcs，5N×1pc，10N×1pc）
Stylus Moving Speed: 35±5 mm/s
Working Distance: 4.72in (120 mm)
Max. Panel Size: 7.8in x 3.9in (200 mm × 100 mm)
Max. Panel Thickness: Less than 1mm
Overall Size: 19.7x10.2x14.9in (500×260×380mm)
Net Weight: 37.5lbs (17 KG)